Color couplers having six-membered rings



Patented June 12, 1945 COLOR COUPLERS HAVING SIX-MEMBERED RINGS Paul W. Vittum, Kearney P. Griffin, and Arnold Weissberger, Rochester, N. Y., asslgnors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application March 4, 1943,

' Serial No. 478,014

9.Claims.

This invention relates to color photography and particularly to color-forming coupler compounds having. six-membered rings.

The use of color-forming compounds which react with the development product of primary aromatic amino developing agents to form 001- ored images on photographic development is well known and has beenthe subject of numerous prior patents. The dyes formed in this way are insoluble in water and in the ordinary photographic developing and fixing baths, although the silver images formed' simultaneously with them during the photographic development 'may be removed from the photographic layer to leave fewer dye images in the layer. The coupler compounds used in this way may be added to the developing solution or in certain cases may be incorporated in the photographic layer prior to exposure.

Color-forming compounds capable of producing yellow dye images upon photographic development have been described, for example, in Mannes and Godowsky U. S. Patents 2,108,602 and 2,113,- 330 and Vittum, Peterson and Porter U. S. Patent 2,271,238. Most of these compounds contain the characteristic group -CO-CH2-CO-- which is typical of many couplers forming yellow dye images. I

We have now found that valuable color-forming compounds for color photography consist of derivatives of hydrogenated heterocyclic nitrogen compounds in which the acyl aceto group is attached directly to the heterocyclic ring at the nitrogen atom. The compounds which we have found suitable have the following general structure:

More specifically our invention comprises compounds in which an acyl aceto group is attached to the nitrogen atom of a six-mem'bered heterocyclic ring containing two or more hydrogenated carbon atoms and having the following structure:

Y CHr-C:

where R=alkyl or aryl Y=oxyzen or CH:.

Specific examples of compounds illustrating our invention are as follows: 1 CHa-CE! CHr-CO-CHr-CON\ /CH:

CHr-CH:

- A'cetoacetpiperldide 2 oat-'05,

CsH|-COCHr-C0N on,

CHz-Ca o-Benzoylacetpiperidlde I a CH-CH CH2 GHQ-C1 N -(m-benzoylacetyl)-1,2,3,4-tetrabydroquinoline 4 CH:CH1 CqHr-C o-cm-oo-rr C Hz-C H1 N-(w-benzoylacetyl)-morpholine of the emulsion layers, the compounds rendered non-diffusing in this way would usually be incorporated in the blue-sensitive emulsion layer since they form yellow dyes.

The following example, which is illustrative only, is a developing solution containing a coupler compound according to our invention:

Solution A:

' p-Aminodimethylaniline sul fate grams 2.5 Sodium sulflte (anhydrous) do '2 Sodium carbonate (anhydrous) do 20 Potassium bromide do 1 Water to liter 1 Solution B:

Acetoacetpiperldide grams; '2

Sodium hydroxide (10% solution cc 10 For use. B is added to A.

The compounds of our invention are prepared by dissolving an ethyl acyl acetate in a suitable solvent and heating the solution with the desired six-membercd ring compound. The following examples illustrate the specific method of preparing two of the compounds which we may use:

Example 1 Acetoacetpiperidide.-To a mixture of 20 cc. of ethylacetoacetate and 20 cc. Of xylene heated in an oil bath at 145 C. was added 10 grams of piperidine in small increments. After heating for 45 minutes, the reaction mixture was Vacuum concentrated and the residue was fractionated at 4 mm. pressure and the product collected at 126-128 C.

Example 2 Benzoylacetpiperidide.-Following the same procedure as Example 1. but using 20 grams of ethyl benzoylacetate and 8 grams of piperidine, and fractionating at 3 microns pressure, 12 grams, B. P. 168-169 C., of benzoylacetpiperidide was obtained.

Our couplers produce dyes which. in general, are less orange, that is, more yellow, than similar dyes previously used for color photography. Accordingly, they have less green light absorption. and are more desirable for purposes of multi-color photography.

The aromatic amino developing agents used with the coupler compounds of our invention include the mono diand tri-aminoaryl compounds and their derivatives formed by substitution in" the amino group as Well as in the rings, such as alkyl phenylene diamines and alkyl toluolene diamines. These compounds are usually employed in the salt form such as the hydrochloride or the sulfate which are more stable than the amines themselves. Suitable developing agents are diethyl-p-phenylenediamine hydrochloride, mono-methyl-p-phenylenediamine hydrochloride, dimethyl p phenylenediamine hydrochloride and 2-amino-5-diethylaminotoluene hydrochloride. The p-aminophenols and their substitution products may also be used where the amino group is unsubstituted. All of these compounds have an unsubstituted amino group which enables the oxidation products of the developer to couple with the color-forming compounds to form a dye image.

It will be understood that the examples and compounds set forth in the present specification are illustrative only and that our invention is to be taken as limited only by the scope of the appended claims.

We claim:

1. The method of producing a colored photographic image in a gelatino-silver halide emulsion layer which comprises exposing the layer and developing it with a primary aromatic amino developing agent in the presence of a coupler compound having the formula:

CHI-CHI where R is selected from the class consisting of alkyl and aryl groups and Y is selected from the class consisting of oxygen and methylene.

2. The method of producing a colored photographic image in a gelatino silver halide emulsion layer which comprises exposing the layer and developing it with a primary aromatic amino developing agent in the presence of a. coupler compound having the formula:

CH:CH:

where R is a. selected from the class consisting of alkyl and aryl groups.

3. The method of producing a colored photographic image in a gelatino-silver halide emulsion layer which comprises exposing the layer and developing it with a primary aromatic amino developing agent in the presence of acetoacetpiperidide.

4. The method of producing a colored photographic image in a gelatino-silver halide emulsion layer which comprises exposing the layer and developing it with a primary aromatic amino developing agent in the presence of w-benzoylacetpiperidide.

5. The method of producing a colored photographic image in a gelatino-silver halid emulsion layer which comprises exposing the layer and developing it with a primary aromatic amino developing agent in the presence of N-(w-benzoylacetyl) -1,2,3,4-tetrahydroquinoline.

6. A color forming photographic developer comprising a primary aromatic amino developing agent and a. coupler compound having the formula:

CH2CH:

where R is selected from the class consisting of alkyl and aryl groups and Y. is selected from the class consisting of oxygen and methylene.

'7. A color forming photographic developer comprising a primary aromatic amino developing agent and a coupler compound having the formula:

where R is selected from the class consisting of alkyl and aryl groups.

8. A photographic emulsion for forming colored images comprising a carrier containing a sensitive silver halide and a coupler compound having the formula:

where R is selected from the class consisting of alkyl and aryl groups and Y is selected from the class consisting of oxygen and methylene.

9. A photographic emulsion for forming colored images comprising a carrier containing a sensitive silver halide and a coupler compound having the formula:

chi-CH,

where R is selected from the class consisting of alkyl and aryl groups.

PAUL W. VITTUM. KEARNEY P. GRIFFIN. ARNOLD WEISSBERGER. 

